If familiar scores are truly stressful for conductors, David Afkham must have been feeling a little tense. His program Saturday night with the Cleveland Orchestra was about as mainstream as they come.

And yet the conductor, leading the last classical concert of the summer at Blossom Music Center, showed no signs of strain. On the contrary, he handled himself and the orchestra beautifully, illuminating the music as if from within.

Performing to a vast crowd on an ideal evening, the newly named principal conductor of the Spanish National Orchestra didn’t go so far as to make anything sound new. With major scores by Beethoven and Schubert, that’s pretty much impossible, not to mention undesirable.

What he did, though, was no less impressive. Somehow, by doing without conceptual foolery, the conductor made the works sound exactly, and more than usually, like themselves, in their purest, most essential forms.

The largest source of potential stress for Afkham would have been Schubert’s “Great” Symphony in C Major, a substantial, landmark work about which most listeners and musicians have preconceptions or expectations. None, though, could have been disappointed by his de facto performance, a reading of remarkable clarity and coherence.

Most striking throughout was the level of togetherness. Under Afkham, the orchestra operated not only as a distinctly responsive, well-oiled machine but also as a unit, in which several individuals shone but no one section took precedence.

Beyond tidy, the playing that resulted was therefore thrillingly crisp and sharp, as if in high-definition. Nowhere was this trait in greater evidence than the Finale, where the trombones rang out resiliently and Schubert’s reams of triplets for the strings hummed in keen precision.

But that’s just one example. In fact, Afkham was sensitive throughout to pictures both long-term and fleeting, demanding a high level of refinement all along the route to lofty, meaningful destinations. The balance he struck in the Andante between volume, tempo and expressive detail was nothing short of perfect.

Afkham wasn’t the only one in a straightforward, lucid state of mind Saturday. Pianist Martin Helmchen, the soloist in Beethoven’s Piano Concerto No. 1, also seemed determined to expose the heart of a popular, deeply familiar piece of music.

Articulation was the hallmark of his performance. Where most pianists rush or blur at least to some minimal extent, Helmchen, in his Cleveland debut, gave each note, including those in ornaments, its full due. So bright and clear was his playing, he might have been sitting at a pianoforte.

Even more poignant was his expressive complexity. Not content with just one mood per movement, Helmchen always sought a counterbalance, injecting playfulness into reveries and a scampering, unbounded quality into music of a generally fiery nature. Thus was routine averted, and a fresh, bracing experience provided in its stead.

Beethoven’s “Coriolan” Overture boasted all these things in microcosm.

No less familiar than its partners on the program, the brief concert opener was another possible stress-inducer. Only the stress evinced by Afkham’s zesty, heavily-punctuated performance was instead of the dramatic variety, and suggested nothing else so much as the title character’s notorious wrath.

Time now to provoke some real stress in Afkham. Time to invite him to Severance Hall.